A bridge output circuit, which supplies a rectangular wave switching voltage to a load by alternately turning on/off a high side transistor and a low side transistor connected in series in response to a change in a rectangular wave input signal level, is known.
In this type of bridge output circuit, there is a period during which both the high side transistor and the low side transistor are turned off simultaneously in order to reliably prevent the high side transistor and the low side transistor from being turned on simultaneously. Such period called a dead time (dead time period). In the related art, a method is generally employed in which a gate voltage of one transistor is used as a feedback signal and the other transistor is turned on after the off state of the one transistor is confirmed.
The dead time is required to suppress a through current caused by the simultaneous turning on of a pair of transistors connected in series, but due to the existence of the dead time, a desired output duty may not be obtained in a half bridge circuit constituted with a pair of transistors. That is, due to the influence of the dead time, a non-negligible deviation may occur between an output duty designated by an input signal and an output duty actually obtained in the half bridge circuit, and this deviation becomes noticeable as a frequency of the input signal increases (this is discussed in more detail later). As a matter of course, it is not desirable to drive a load with an output duty deviating significantly from the output duty designated by the input signal.